In the use of axial flow type combines, in which rotor means extend substanitally longitudinally from an inlet end of a threshing compartment for coaction with a concave to effect threshing of crop materials of different kinds, it has been found to be effective to provide auger means on the forward ends of said rotors for effecting desirable delivery of the crop material from the upper end of an elevator into the inlet end of said threshing compartment. However, it also has been found that particularly in regard to certain crop conditions, combines that have an auger type infeed tend to bunch or rope the material together as it is moved from said elevator axially into said threshing compartment. When harvesting crops that produce so called tough threshing conditions, the concave and rasp bars on the rotor must be set at an extremely close setting and this situation, combined with material that is bunched when fed to said threshing compartment causes a thumping and reduced feeding capacity in the combine, as well as increased wear of the rasp bars and a certain amount of damage to kernels or grains which are threshed under such close setting conditions.
One typical example of a type of combine which has become very popular in recent years comprises the subject matter of U.S. Pat. No. 3,848,609, dated Nov. 19, 1974, to Mortier et al. In said combine, there is a conventional type of header at the forward end which includes cutter means and consolidating auger means which deliver a steady stream of said material to an elevator which moves the crop material upward and rearward to the auger which then forceably delivers the material to the inlet end of the threshing compartment, which exists between the rotor which has rasp bars thereon, and a concave which is generally along the lower portion of the rotor. In the combine specifically illustrated in said patent, a pair of rotors and cooperating concaves are provided but is to be understood that certain types of combines also have only a single rotor and concave.
When bunching of the crop material or the formation of a rope-like consistency thereof occurs in the delivery of the material to the auger and threshing compartment of the combines referred to above, the threshing components of the combine are subjected to abnormal wear and, in addition, substantial power is required to be provided in the combine to operate it for purposes of enabling the same to cope with such abnormal conditions of bunched material as introduced to the threshing compartment, as distinguished from a relatively even or smooth flow of material being delivered to said threshing compartment. The thumping resulting from such condition not only is objectionable to the operator of the combine but, even more importantly, the threshing components of the combine either can be damaged or it is necessary to construct the same in a sufficiently heavy design to handle such abnormal conditions without damage and obviously this results in increased cost of manufacturing the combine.